I wouldn't use poison, you never know where they'll choose to expire - it may be somewhere inaccessible, but within "smelling distance". Plus that's dangerous for pets.
I didn't use traps. As mentioned, they have to be checked frequently, not to mention that where we parked our rig for the winter was near the woods. Catch 10, another 10,000 were ready to take their place, and to check the traps I may have had to trudge through waist high snow and clear the area all around the coach to get to them.
The formula I finally settled on was moth balls in the storage bays and engine/generator compartments, Fresh Cab in all the interior storage spaces (cabinets, drawers, under the bed and sofas). You don't want to use the mothballs inside, it takes forever to get rid of the smell. For the mothballs I'd buy a package of those "footies" women wear like socks, under slacks, so it looks like they are wearing nylons. Put half a dozen or so mothballs in each and distribute them around.
Once I landed on this formula, no more mice in the motorhome.
Jay & Peggy Monroe with Dolly
Can't take it with you - don't plan on leaving any behind
2016 Newmar London Aire 4553, Spartan chassis
Wrangler Unlimited toad